MinimumTimeDifference.java

import java.util.*;

public class MinimumTimeDifference {
    public int findMinDifference(List<String> timePoints) {

        System.out.println("Given hours: " + Arrays.toString(timePoints.toArray()));
        int minimum = Integer.MAX_VALUE;

        List<Integer> minutesList = getMins(timePoints);
        Collections.sort(minutesList);
        int first = minutesList.get(0);
        int last = minutesList.get(minutesList.size()-1);
        minimum = Math.min(minimum, first+1440-last);
        int prev = minutesList.get(0);
        for(int i=1;i<minutesList.size();i++){
            int x = minutesList.get(i)-prev;
            int y = prev + 1440 -  minutesList.get(i);
            minimum = Math.min(Math.min(x, y), minimum);
            prev =  minutesList.get(i);
        }
        System.out.println("minimum time difference: " + minimum);
        return minimum;
    }

    private List<Integer> getMins(List<String> timePoints){
        List<Integer> minutesList = new ArrayList<>();
        for(int i=0;i<timePoints.size();i++) {

            String[] temp = timePoints.get(i).split(":");
            int hour = Integer.parseInt(temp[0]);
            int min = Integer.parseInt(temp[1]) + 60 * hour;
            minutesList.add(min);
        }
        return minutesList;
    }

    public static void main(String[] args) {
        List<String> timePoints = new ArrayList<>();
        timePoints.add("01:59");
        timePoints.add("03:00");
        timePoints.add("21:50");
        timePoints.add("22:30");
        MinimumTimeDifference m = new MinimumTimeDifference();
        m.findMinDifference(timePoints);
    }
}